Ofatumumab is a fully human monoclonal anti-CD20 antibody increasingly used in Nephrotic Syndrome patients with failure or intolerance to Rituximab. Similarly to other antiCD20 antibodies, infusion-related reactions are reported and prevented by systematic premedication. We describe our infusion protocole based on a higher concentration of ofatumumab than previously reported (in 500ml versus 1000ml of saline serum) and its tolerance.

Material and methods:

We retrospectively analysed 63 ofatumumab infusions in 21 patients. Median age at diagnosis was 3,2 years and at treatment 9 years. All patients had previously received rituximab, with failure to obtain B cell depletion in 13 patients. Patients with Steroid and multidrug Dependant NS (n=16) received a 750mg/1.73m2 infusion, that could be repeated after B cell recovery. Patients with Multi-Drug Resistant NS (n=5) received a first infusion of 300mg/1.73m2 followed by 5 weekly infusions of 2000mg/1.73m2. Ofatumumab was diluted in 500 ml of normal saline and infused, after systematic premedication by paracetamol, methylprednisolone and dexchlorphéniramine,at constant rates from 3 to 200ml/h at first dose and 12 to 200 ml/h at others.